Web stretching and shrinking device



Dec. 1, 1970 1'. A. HELMINEN 3,543,365

WEB STRETCHING AND SHRINKING DEVICE Filed June 1, 1967 ZSheets-Sheet 1 n 00 w 20 F/g./ 50 '50 0 w 68 o D m 30 F a 2 58 lg 72 as 8682 82 Tail/o A. He/minen INVENTOR.

k 1 BY and M Mm Dec. 1, 1970 'r. A. HELMINEN WEB STRETCHING AND SHRINKING DEVICE 2 Sheets-Sheet 2 Filed June 1, 1967 mm k .0 mm km wk an um mm 6% 1 O m av v v M 9k T oil/o A. He/minen lNl ENTOK.

WW vv United States Patent 015cc 3,543,365 WEB STRETCHING AND SHRINKIN G DEVICE Toivo A. Helminen, 12 Crestview Drive, Appleton, Wis. 54911 Filed June 1, 1967, Ser. No. 642,876 Int. Cl. B29c 17/07 U.S. Cl. 29-113 Claims ABSTRACT OF THE DISCLOSURE Adjustable roller device for shrinking or stretching a continuously moving web in width during the manufacture of paper. A web of paper while in a semiplastic state is passed in contact with a circumferential portion of the roller undergoing a change in axial length on its peripheral contact surfaces to correspondingly change the width of the web.

BACKGROUND OF THE INVENTION This invention relates to the expansion or contraction of a continuously moving web to a desired width during the manufacture of paper.

It is common practice to either shrink or stretch a paper web while in a semiplastic state by passing the web in contact with one or more roller devices in order to effect the desired dimensional change in the web while in contact with the roller devices.

In some roller devices, the web contacting surface has been formed with a curvature in order to effect either shrinking or stretching of the web. Aside from the severe limiation imposed upon the dimensional change possible with such roller devices, the use of the curved surface technique has resulted in non-uniform elongation or shrinkage of the web. Further because of the curvature involved, the use of a plurality of rollers in order to progressively shrink or expand the web was not possible.

Another technique utilized in effecting shrinkage or stretching of a web, has been to progressively pass the web in contact with rollers of axially increasing or decreasing length. This method however, involves lateral surface friction and requires shut-down in order to affect any adjustment.

The present invention avoids the drawbacks and disadvantages associated with prior art techniques aforementioned and is therefore capable of effecting shrinkage or stretching of a web without use of any curved contact surface so that one or more roller devices may be utilized. Also, adjustment in the amount of dimensional change may be effected during operation without requiring any shut-down of the paper manufacturing equipment.

SUMMARY OF THE INVENTION In accordance with the present invention, a roller de vice is utilized to effect shrinkage or laterial elongation of a continuously moving web by contact with a circumferential portion of the roller device undergoing a variation in axial length so as to correspondingly vary the lateral dimension or width of the web in contact therewith.

The roller device of the present invention is made up of relatively rigid axial end portions which are interconnected by a tubular portion made of an elastically flexible material enclosing a chamber that is pressurized by a suitable fluid such as air in order to maintain the web substantially flat as it approaches or departs from the roller surface.

The roller device also features facilities for adjusting the angular position of the rigid end portions aforementioned in order to change the amount of web elongation while the web is moving at high speed. The amount of 3,543,365 Patented Dec. 1, 1970 shrinkage or lateral elongation of the web may also be controlled in accordance with the degree of wrap of the web about the tubular portion of the roller and the number of roller devices about which the web is wrapped.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWING {FIGURES FIG. 1 is a top plan view of a web stretching or shrinking roller device constructed in accordance with the present invention.

FIG. 2 is a side elevational view of the roller device shown in FIG. 1.

FIG. 3 is an enlarged partial sectional view through the roller device taken substantially through a plane indicated by section line 33 of FIG. 1.

FIG. 4 is a transverse sectional view taken substantially through a plane indicated by section line 4--4 in FIG. 3.

FIG. 5 is a perspective view of a portion of the roller device with a web wrapped around a portion thereof.

FIG. 6 is a diagrammmatic transverse sectional view through the roller device showing the angle of wrap.

FIG. 7 is a partial longitudinal sectional view through a modified form of roller device.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail, FIGS. 1 and 2' illustrate a roller device generally denoted by reference numeral 10 adapted to be mounted in proper position in a paper manufacturing process line so as to receive the web of paper in a semiplastic state. A stationary support frame is therefore provided for the roller device including a pair of spaced frame supports 12 and 14, each of which mounts spaced bearing assemblies 16 between which a pivotal support member 18 is positioned in an adjusted angular position about an axis extending through pivot shafts 20 that extend laterally from the support member 18 for journalling by the bearing assemblies 16. The support members 18 rotatably mount a roller shaft assembly generally referred to by reference numeral 22 including end shaft sections 24 and 26 on opposite axial sides of a spacer shaft section 46. Thus, separate axes extend through the shaft sections 24 and 26 which intersect the general rotational axis of the roller device at intersections spaced from the pivotal axes extending through the pivot shafts 20. The angular position of the support members 18 about the pivotal axes are adjusted in one form of the invention by means of an adjustment assembly generally referred to by reference numeral 28 that interconnects the support members 18 as will be hereafter explained.

Referring now to FIG. 3 in particular, it will be observed that the roller device includes a pair of relatively rigid end portions 30 and 32 respectively provided with tubular extensions 34 and 36 to which the shaft sections 24 and 26 are keyed. Each support member 18 rotatably mounts a roller end portion and associated shaft section between a bearing assembly 38 through which the shaft extension extends and a bearing assembly 40 mounted on the tubular extension of the roller end portion Within the tubular housing portion 42 of the support member 18. One of the shaft sections 24 may be provided with a splined end section 44 to which a suitable prime mover (not shown) may be drivingly connected if the roller device is to be independently powered. Where a rela- 3 tively strong web is involved, drive may be imparted to the roller device from the web itself.

The rotational axis for the roller device extends through the spacer shaft section 46 that includes universal joint assemblies 48 at opposite axial ends interconnected with the shaft sections 24 and 26 as aforementioned. The axes of the shaft sections and spacer shaft intersect at the axes of the pivot shafts 20 for rotation of the tubular portion 50 about the rotational axis of the roller device perpendicular to the direction in which the web is travelling. The tubular portion 50 is made of an elastically flexible material such as rubber, the axial ends of which are anchored to the roller end portions 30 and 32 by anchor plates 52 and fasteners 54.

In the modified form shown in FIG. 7, the tubular portion 50 is secured to the end portions by tie bands 52' aligned with annular grooves 54' formed in the end portions very close to end planes between which the tubular portion freely extends. The tubular portion 50 is prevented from collapsing radially inwardly by means of a lubricant bearing film slidably spacing the tubular portion from the radially outer cylindrical surface of a rigid tubular portion 49 associated with the spacer shaft assembly 46'. Also, in this form of the invention, the angular relationship between the shaft sections and the spacer shaft assembly is fixed.

The tubular portion 50 of the roller device encloses a pressure sealed chamber 56 to which fluid under pressure is supplied from any suitable source (not shown). A conduit 58 connects the source to the chamber 56 through a stationary manifold device 60 mounted in sealed relation on the shaft section on either axial side of the manifold device 60. A flexible conduit 64 interconnects one of the glands 62 with the tubular extension 34 of the roller end portion 30 so that fluid may flow through a bore 66 formed therein into the fluid chamber 56 provided with a pressure relief valve 59 on the end portion 32. The pressure within the chamber 56 may be monitored by a fluid pressure gauge 68 which interconnects the conduit 58 with the manifold device 60. The level of pressure maintained within the chamber 56 may be set to support a web 70, diagrammatically shown in FIG. 5, in a substantial flat condition as it approaches or departs from the roller device about which it is grapped. Thus, the major intermediate portion of the roller 50 is maintained substantially cylindrical as shown in FIGS. and 6 while in contact with the web 70. Bending of the tubular portion by the web tension, producing a resultant bending force '51 as shown, would be prevented by the supporting action of the bearing film on the rigid portion 49 of the spacer shaft assembly in FIG. 7 form of the invention. The diameter of portion 49 is therefore selected to accommodate the smallest diameter assumed by the tubular portion when the end portions 30 and 32' are angularly adjusted to extreme positions.

In the installation shown in FIGS. 13, each of the support members 18 is provided with a lower leg portion 72 pivotally connected by a pin 74 to an internally threaded nut member 76. The nut members 76 receive externally threaded screw members 78 and 80 which are interconnected by a connector shaft 82. The screw members 78 and 80 are threaded in opposite directions so that when the adjustment assembly 28 is rotated by means of the adjustment hand wheel 84 connected to the end of screw member 78, the nut members 76 will be axially displaced in opposite directions to angularly displace the support members 18 by equal amounts in opposite directions about the pivotal axes extending through the pivot shafts 20. The support members 18 and the roller end portions 30 and 32 may thereby be adjusted to positions indicated on a calibrated scale element 86 secured to and extending axially from one of the nut members 76 as shown in FIG. 2 in overlapping relation to the connector shaft 82. The spacing between the index edge 88 of the connector shaft and the nut members 76 therefore gauges 4 the amount of dimensional change to be effected by the roller device.

From the foregoing description, it will be appreciated that the amount of shrinkage or elongation will depend upon the angular position of the roller end portions 30 and 32 or the support members 18 on which they are rotatably mounted about the separate rotational axes extending through the shaft section 24 and 26 of the drive assembly, this angular position being reflected by the angle or as shown in FIG. 5 between the separate axes of the roller end portions and the rotational axis of the roller extending through the connecting shaft assembly 46. It will be apparent therefore, that the axial length of the tubular portion 50 will vary from a minimum value to a maximum value between diametrically opposite locations by an amount depending on the angle 04. Since the web 70 is in contact with the peripheral outer surface of the tubular portion 50 of the roller device, it will undergo a dimensional change corresponding to this change in axial length of the tubular portion 50 along its circumference as the roller device is rotated. The amount of dimensional change imparted to the web 70 will also depend upon the angle of wrap B as diagrammed in FIG. 6 between the lines of tangency 90 and 92 that extend along the axial length of the tubular portion '50. The web 70 approaches or departs from these lines of tangency 90 and 92 which are substantially straight by accordingly regulating the internal pressure of the chamber 56. Thus, the web will undergo a change in width 5 equal to the difference between L and L as diagrammed in FIG. 5 in accordance with the equation, e=D, sin a (1-cos ,8), which may be readily derived from the geometry involved. Thus, the scale element 86 shown in FIG. 2 may be appropriately calibrated so that the operator may effect a change in the desired elongation or shrinkage of the web during operation. Further, since the web approaches and departs from the roller device in a flat condition in the described installation, a plurality of such variable roller devices may be similarly utilized with fixed roller devices in order to progressively elongate or shrink the web. It is also possible to control the variable roller device so as to angularly adjust the position of one of the end shaft sections relative to the other in response to lateral shift of the web in order to compensate for such lateral shift. In such case the roller device acts as a web guide. Several roller devices as described may also be positioned between fixed guide rollers for holding the web in a flat condition as it is being progressively changed in width. The change in web width could of course also be varied by increasing the internal pressure of the chamber 56 to produce a surface curvature along the roller portion 50.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. Apparatus for dimensionally changing a continuously moving web of material in a direction transverse to the direction of travel of said web comprising a roller having relatively rigid end portions interconnected by a relatively flexible tubular portion, means rotatably mounting said end portions about separate axes for circumferential variation in axial length of the tubular portion in response to rotation of the roller, spacer means interconnecting said end portions in axially fixed relation to each other establishing a rotational axis for the roller perpendicular to said direction of travel, and fluid pressure means connected to the roller for supporting the web in contact with the tubular portion.

2. The combination of claim 1 including adjustment means operatively connected to the rotational mounting means for varying the angle between said separate axes of the end portions and the rotational axis of the roller during rotation thereof.

3. The combination of claim 2 wherein said spacer means includes a shaft extending through the tubular portion having opposite ends pivotally connected to shaft sections rotatably mounted by the rotational mounting means about the separate axes of the end portions.

4. The combination of claim 3 wherein said rotational mounting means comprises a support frame, a pair of support members pivotally mounted by the support frame, and bearing means carried by the support members rotatably mounting the end portions about said separate axes, said support members being interconnected by the adjustment means in predetermined angular positions relative to the rotational axis.

5. The combination of claim 1 wherein said rotational mounting means comprises a support frame, a pair of support members pivotally mounted by the support frame and bearing means carried by the support members rotatably mounting the end portions about said separate axes.

6. The combination of claim 5 wherein said spacer means includes atpair of shaft sections rotatably mounted by the rotational mounting means for the end portions of the roller, and a spacer shaft extending through the tubular portion having opposite ends pivotally connected to the shaft sections.

7. The combination of claim 1 wherein said spacer means includes a pair of shaft sections rotatably mounted by the rotational mounting means for the end portions of the roller, and a spacer section extending through the tubular portion having opposite ends pivotally connected to the shaft sections and an intermediate rigid surface supporting a bearing film preventing collapse of the tubular portion.

8. Apparatus for dimensionally changing a continuously moving web of material in a direction transverse to the direction of travel of said web comprising a roller having relatively rigid end portions interconnected by a relatively flexible portion, means rotatably mounting the end portions in response to rotation of the roller, means for passing the web in contact with a contact surface of the flexible portion while undergoing said variation in axial length, and support means for maintaining the contact surface of the flexible portion substantially cylindrical while in contact with the web.

9. The combination of claim 8 wherein said flexible portion of the roller is made of an imperforate, elastic material.

10. The combination of claim 8 including spacer means interconnecting the end portions of the roller for rotation about a rotational axis parallel to the axis of said cylindrical contact surface.

References Cited UNITED STATES PATENTS 2,130,007 9/ 1938 Haas 26-18.6 2,689,392 9/ 1954 Robertson 29-113 2,898,662 8/1959 Robertson 29--113 3,023,695 3/1962 Kusters 29-113 REUBEN FRIEDMAN, Primary Examiner T. A. GRANGER, Assistant Examiner US. Cl. X.R. 26-63 

